it stops checking the entire PSX disc for full hash check every time the launcher runs, assuming the user's hash checked it when selecting the disc the first time and saving it to settings, so it just validates the file name and size instead, then it shares lifecycle with the launcher and the game to load the game faster, and several optimizations were made to loadstate paths which I think in the end relied on reanchoring host timings to the restored clock that came with the state
Alex Vanderveen